1. Field of the Invention
The present invention relates to speech recognition and more specification to using meta-data dependent language modeling for speech recognition.
2. Introduction
Speech recognition has gained momentum as a viable technology over time. As computer processors improve and as the language models and recognition algorithms improve, the recognition accuracy for systems that perform speech recognition also improve. One way used by those of skill in the art to improve automatic speech recognition (ASR) is to use language models that have many recognition examples and samples within a certain “domain.” For example, if a speech recognition engine is to recognize speech from a person who will be talking about making a flight reservation, then there is a known world of words and phrases that are expected to be spoken by the user. The speech recognition engine and the experts designing the system can make use of commonly used words for that domain to improve recognition.
A language model used by a speech recognition engine needs to be “trained” to recognize speech. This typically involves experts recording average or expected discussions between a person and the system, labeling that data, and creating the language model. For example, the expert may record a person saying “I want to fly from LA to New York”. The person would then label the terms used “LA”, “New York” and so forth so that the system, when faced with similar sounding words in live use, will associate the appropriate sound with the appropriate word. With enough training data that covers many scenarios, the language model is ready for live use to listen to real users.
There are still many challenges with providing a speech recognition application that approaches acceptable recognition accuracy such that its use will become widespread. While many technologies exist to help improve accuracy, there is a need in the art to consider extending the information used by a recognition engine beyond what is presently available to further improve the technology.